Musical instrument



Nov. 25, 1941. D. P. oBRlEN MUSICAL INSTRUMENT Filed April 26, 1941 L9 1l 1, l? 1f l 11 l l -If 17; ML; im 2 U T y La L7 I? 1s d 11 2% Z0 1g anielH wzjen,

INVENTOR.

AT TRNEY.'

Patented Nov. 25, 1941 UNITED STATES PATENT OFFICE Musical. ms'raum'r omen r. orim. summa, com

application Aun zs, 1941, serai No. :90,441

(cl. x14-1.15)

ZCIaims.

The invention here disclosed relates to musical instruments of the piano type, having hmed strings, reeds, bars or the like which are vibrated to create the desired musical sounds.

Objects of the invention are to obtain with such instruments, further or additional desirable or amplied sound effects and particularly to accomplish this without impairing or objectionably affecting the sonorous or individualistic characteristics of the original instrument.

Thus it is a, further object of the invention to provide sound amplifying means for building up the tone and volumecharacteristics of a piano and which will be directly applicable to such an instrument without modifying, changing or eliminating any functional parts of the piano and which will retain and utilize to the full extent, the sonorous quality of the soundboard and the other desirable characteristic elements of such an instrument.

Other and further objects of the invention are to provide structural means for accomplishment of the foregoing which will be of simple, inexpensive iorm, taking up small space and readily applicable to existing musical instruments.

Other desirable objects and accomplishments of the invention will appear as the specification proceeds.

The novel features of structure and combinations of parts by which the purposes of the invention are attained are set forth in the specification following, broadly covered in the claims and illustrated by way of example in the accompanying drawing.

Fig. 1 is a broken partly tic plan view illustrating an application of the invention to a grand piano.

Fig. 2 is an enlarged broken view as on substantially the plane of line 2-2 of Fig. 1, showing the pickup for the lower register or bass section, the strings appearing in section and indicating diagrammatically an amplifier and sound reproducer connected with the pickup coil.

Fig.3isabrokenbottomplanviewotparis shown in Fig. 2.

Fig. 4 is a diagrammatic representation and partsectiona1viewasonline4-4ofFig.2.

In the present disclosure, a practical enbodiment of the invention is shown applied to and combined with a grand piano having the usual plateorframe I,carryingthestrings6,'|andl of the lower, middle and upper the soundboard 9 and other usual parts of such an instrument being present and by In the present illustration, a separate single pickup is provided for each of the three string sections of the piano and each one of these pickups, as particularly shown in the detail views, Figs. 2, 3 and 4, comprises a permanent magnet Il supported across the strings by a bridge piece Il and carrying a ilat pickup coil I2 extending about all the strings of that group.

The supporting elements Il may be simply pieces of wood of the proper length, rested or secured on the rib portions of the frame in proper position to hold the magnets il over the strings and the flat coil I2 freely surrounding the particular group of strings.

The magnets il, of which there are three in the illustration, are shown as permanent bar magnets-polarized transversely, across a lesser dimension and arranged with the poles vertically disposed, to project magnetic fields such as indicated at I3 in Fig. 4, intercepting the wires of the coils and inducing currents therein.

The tuned strings, set into vibration in this instance by the hammers of the piano, extending freely through the coils, vary the E. M. F. induced in the coils, in accordance with amplitude, direction and continuity of vibration.

Accordingly, amplifying and reproducing apparatus such as that represented by the ampliiier il and speaker l5 in Fig. 2, connected with the coil as by wiring I6, will build up and create tonal effects related to those originated by the vibrating strings.

Sustained sound effects are obtainable so long as the strings continue in vibration and this, in the illustration, may be controlled by holding down the keys for so long as such effects are desired. On the other hand, instantaneous cutoff isobtained whenakeyisreleased because of the damper operation of the piano action.

'Ihe resonating, sonorous and other desirable characteristics of the soundboard also are utilized in the present invention since it is undisturbed and left free to fully cooperate with the strings. In fact, the soimdboard may desirably be utilized astheresonatorelementofthespeakerand which may be accomplished by mounting the speaker imit so as to apply itsvibrating impulses direct to this board.

'Ihe piup coil, surrounding all the strings of a group, such as the bass, voice or treble group, is operative to pick up vibrations of adjoining strings in a group set in motion by. sympathetic reaction.

The invention is effective with .strings of nonapplication of the invention to the instrument. 55 magnetic as well as with the usual steel piano wire strings, because of the eddy currents created in the non-magnetic wires.

By providing separate pickups for the bass, middle and upper registers, the matter of installation in the piano is simplified. One or more or all such pickups may be installed or used and in playing, any one of such controls may be amplified to greater or lesser extent in respect to the others, thus to bring out different desired musical effects.

Various means may be employed for securing the parts. In the illustration, bands l1 are shown passed about the magnets I and the supports or struts Ii, these bands secured at the top by screws I8, and in similar fashion, the coils are shown secured to the bottom of the magnets I0 by bands I9 secured at the top by screws 20.

The provision of a separate pickup for each string group enables use of speakers best suited to the respective groups, or using to advantage, a speaker of the coaxial type having separate socalled tweeter and woofer sections and which, for example, may be connected respectively with the treble and bass pickup coils.

Various electrical connections may be employed. The different pickup coils may be connected, through amplifiers,` with different speakers or with individualized sections of the same speaker and they may be connected in parallel or in series order with the same or different speakers, as found to give the best desired results under various circumstances.

While one magnet to each coil, exending longitudinally of the coil and polarized transversely across the coil, is practical and desirable, it is contemplated that a second, oppositely poled magnet may be placed at the opposite side of the pickup coil. While electromagnets may be used, permanent bar magnets are preferred, because of their occupying less space for the magnetic force provided and the freedom from external energizing circuits, etc. These permanent magnets may be of nickel-aluminum alloy, the same having been found to provide the desired high degree of magnetic force within the necessary space limits and for an indenite period of time.

What is claimed is:

1. A musical instrument, comprising tuned vibrating sound emitting elements, an elongated pickup coil looped about said tuned vibrating sound elements, an elongated permanent magnet extending along one side (only) of said elongated coil and polarized along a transverse dimension of the same and sound reproducing means connected with said pickup coil.

2. A musical instrument, comprising tuned metallic strings, an elongated pickup coil looped transversely about said strings, an elongated permanent magnet at the outside of said coil and extending along one side only of said elongated coil, said magnet being polarized along a transverse dimension and creating a magnetic field extending in the direction of extent of said tuned metallic strings and sound reproducing means connected with said elongated pickup coil.

DANIEL P. OBRIEN. 

